1. Field of the Invention
This invention relates to a unitary elastomeric wedge for imparting an orthodontic rotational force to a tooth.
2. Description of the Related Art
Rotation wedges are often used during orthodontic treatment to rotate a tooth about its own long axis. Typically, rotation wedges are formed from an elastomeric material and are positioned adjacent the mesial or distal side of a bracket between the surface of the tooth and an archwire. The wedges are compressed when initially installed, and the inherent resiliency of the elastomeric material tends to rotate the tooth toward a desired orientation
One type of rotation wedge known in the art is described in U.S. Pat. No. 4,340,363 and includes a wedge portion having a pair of spaced apart projections defining an archwire channel, as well as a planar portion with a pair of spaced apertures sized to receive one pair of tiewings of a standard twin orthodontic bracket. Another type of rotation wedge is described in U.S. Pat. No. 3,913,228 and includes a wedge portion that is integrally connected with a single loop adapted to be stretched somewhat when installed over two tiewings on one side of a twin bracket.
The aforementioned rotation wedges, however, cannot be placed in a position for use unless the archwire is first removed from the bracket to provide sufficient access to place the loop or apertures around the tiewings and behind a location to be subsequently occupied by the archwire. Moreover, once such wedges are in place, the orthodontist must then reposition the archwire and ligate the archwire to the bracket using a separate ligature tie or ring.